Feedback needed on concrete work
So I finally got this slab poured yesterday, by the guy who is my contractor friend. Let me preface my question(s) with the disclaimer that he had put an addition on my barn which included pouring a slab for the floor that turned out just fine.
He used rebar for this job. The slab was ~six in., ~35X30. The slab is in four "squares." As regarding the rebar, he laid it out in a grid which extended under the cross forms (not the perimeter). That is, each square did not have its own grid and the bar was laying on the ground. I brought to his attention that there wouldn't be much reinforcement that way and he assured me that they would lift it up during the pour so it would end up in the bulk of the concrete. Seeing as how the grid was on the ground under the cross forms I didn't really see how that was going to work so well. And in fact I don't think it did.
While pouring the second square they had too much concrete and so shoveled the excess into what turned out to be square four. In the mean time it was walked on, a lot, and by the time square four was poured it was pretty hard. Is that concrete now part of the slab, or is the slab thinner in those areas by the thickness of the hardened material?
In two of the squares they didn't do such a good job screeding and there are undulations. I mean, put a level across the top and there is an 1/2 - 3/4 in. space underneath. Is this something I should make an issue of? I really don't consider this to be acceptable but if it sounds like it's within some industry acceptable standard I can live with it. If it isn't, how can it be made reasonably flat?
He used pressure treated 2X4 for the cross frame, which means there is concrete beneath the wood. Is that an issue, like is that now a two inch slab with a piece of wood on top of it? The wood was left in place as the expansion joints. Also, the wood sits proud of the concrete surface for some lengths depending on how well they screed. Should I ask that it be knocked down? It looks to me that it's going to be a problem the first time I plow this winter.
This slab has to support the weight of tri-axle loads of logs driving over it a few times a year.
I'd like to hear some comments, mainly constructive in nature if possible.